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    <meta charset="UTF-8" />
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    <title>Document</title>
  </head>
  <body>
    <script>
      function Star(uname, age) {
        this.uname = uname
        this.age = age
      }
      let that
      Star.prototype = {
        constructor: Star,
        sing: function () {
          console.log('我会唱歌')
          that = this
        },
        movie: function () {
          console.log('我会演电影')
        }
      }

      var ldh = new Star('理解', 18)
      var zxy = new Star('张佳羽', 19)
      // c1
      console.log(that === ldh)
// c2
      ldh.sing()
      console.log('b2', that === ldh)
    </script>
  </body>
</html>
